Optimizing Animated GIFs / Calculate the Differences

Calculate the Differences

Optimizing Animated GIFs

Now that you've created an optimized global palette it's time to optimize your frames. If you have access to GIFWizard you can skip this step. Using Debabelizer's "compare" feature, calculate the difference (the pixels that have changed) between each frame (i.e., frame 1 and 2 = 2d). Open the first frame and select Misc | Compare, select the next frame and Debabelizer finds only the pixels that have changed between these two frames; see Figure 14. Set the compare options to change unchanged pixels to your key color, so you can drop it out later using GIFBuilder's transparency feature. Save the frame uncropped.